Multi-input,multi-output flight control system design for the YF-16 using nonlinear QFT and pilot compensation

Nonlinear quantitative feedback theory (QFT) and pilot compensation techniques are used to design a 2 × 2 flight control system for the YF-16 aircraft over a large range of plant uncertainty. The design is based on numerical input-output time histories generated with a FORTRAN implemented nonlinear simulation of the YF-16. The first step of the design process is the generation of a set of equivalent linear time-invariant (LTI) plant models to represent the actual nonlinear plant. It has been proven that the solution to the equivalent plant problem is guaranteed to solve the original nonlinear problem. Standard QFT techniques are then used in the design synthesis based on the equivalent plant models. A detailed mathematical development of the method used to develop these equivalent LTI plant models is provided. After this inner-loop design, pilot compensation is developed to reduce the pilot's workload. This outer-loop design is also based on a set of equivalent LTI plant models. This is accomplished by modelling the pilot with parameters that result in good handling qualities ratings, and developing the necessary compensation to force the desired system responses.     

MULTIMEDIA NETWORKING A Leading-Edge Communication Technology

The realization of digital multimedia's full business potential requires networking. This article discusses the value-added benefits to the corporation of networked multimedia as well as the choice of architectures and technologies needed to deliver multimedia networking solutions.     

REENGINEERING METHODOLOGIES AND TOOLS A Prescription for Enhancing Success

Companies are seeking methodologies and tools to facilitate well-disciplined and organized ways of structuring, assessing, and resolving the issues that business process reengineering raises. This article reviews approaches to BPR that can better your odds of success.     

REENGINEERING DONE RIGHT Intermediate Solutions That Are Cost-Effective

Effective systems development techniques attract a lot of attention, but little has been done to effectively address systems maintenance. This article describes an effective, proven approach to resurrecting existing systems and Increasing their useful life, using a system that employs both software tools and a rigorous methodology.     

UTEC and Ferut: the University of Toronto's computation centre

Although not well known, the University of Toronto had a very early computer-development program and in 1952 was one of the first few institutions with an operable computer in North America. This article describes the university's initial attempt to build the UTEC computer and how it acquired the pioneering Ferut machine     

Generalized chebyshev inequality and its application to survivability analysis of complex systems

Conclusions The generalized Chebyshev inequalities are of independent value in mathematical analysis, probability theory, and other fields. Survivability analysis of elements and systems requires specification of functional probability characteristics-distributions of the current durability point. Probabilistic calculation of survivability of complex systems can be carried out using logical-probabilistic methods [22, 28], because the probabilistic-physical meaning of the distribution of current durability point at the point x is the failure probability of an element (a system) given the deterministic level x of the next shock. The methodology of reliability theory can be updated by focusing on a physical stochastic process, instead of time to failure, as the cause of failure. In conclusion, I would like to thank I. A. Ibragimov for discussion of results and some useful comments. Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 159–166, March–April, 1994.     

Nonlocal quasi-Newton method for solving convex variational inequalities

Conclusion In the optimization problem [f ₀(x)│h_i(x)<-0,i=1,…,l] relaxation of the functionf ₀(x)+Nh⁺(x) does not produce, as we know [6, 7], α_k=1 in Newton's method with the auxiliary problem (5), (6), whereF(x)=f _0′(x). For this reason, Newton type methods based on relaxation off ₀(x)+Nh⁺(x) are not superlinearly convergent (so-called Maratos effect). The results of this article indicate that if (F(x)=f _0′(x), then replacement of the initial optimization problem with a larger equivalent problem (7) eliminates the Maratos effect in the proposed quasi-Newton method. This result is mainly of theoretical interest, because Newton type optimization methods in the space of the variablesx ∈R ⁿ are less complex. However to the best of our knowledge, the difficulties with nonlocal convergence arising in these methods (choice of parameters, etc.) have not been fully resolved [10, 11]. The discussion of these difficulties and comparison with the proposed method fall outside the scope of the present article, which focuses on solution of variational inequalities (1), (2) for the general caseF′(x)≠F′ ^T(x). Translated from Kibernetika i Sistemnyi Analiz, No. 6, pp. 78–91, November–December, 1994.